The present invention relates to a compressor system, and more particularly, to a compressor system having an improved structure so that noise and vibrations are reduced and miniaturization is easily achieved.
A type of compressor which increases the pressure of a gas and exhausts the compressed gas is a rotor-type compressor. The rotor-type compressor has a pair of rotors, female and male which are respectively installed on two axes in parallel and rotate interlockingly. While rotating, the female and male rotors take in, compress and exhaust gas. In doing so, oil is supplied to reduce abrasion and heating occurring due to friction between the rotating female and male rotors.
FIG. 1 schematically shows a conventional rotor-type compressor system. Reference numeral 27 indicates a housing for accommodating elements of the compressor system in which a grilled air passage 28 is formed at one side surface. Reference numeral 3 indicates a compressor main unit in which a pair of rotors 3a for compressing air taken in through an air cleaner 4 are installed. The rotors 3a are rotated by a driving motor 1, and the air compressed by the rotor 3a is supplied to an accumulator 5 via an exhaust pipe 3b. The accumulator 5 is usually fabricated by molding or welding several metal plates. A cooling oil is supplied to the rotor 3a through a first oil supply pipe 21 to reduce abrasion and heating due to the pair of rotors 3a which rotate while interlocking with each other, and thermal expansion of the rotor 3a due to the heat.
An oil separator 7 is installed inside the accumulator 5 and separates oil 6a included in the compressed air which is supplied through the exhaust pipe 3b. That is, a portion of the oil which is splashed together with the compressed air to the accumulator 5 precipitates down and then is stored in the accumulator 5, and the remaining portion of the oil sticks to the oil separator 7. The oil stuck to the oil separator 7 is supplied to a bearing (not shown) installed on the axis of the rotor 3a via an auxiliary oil line 25.
The compressed air passed through the oil separator 7 is supplied to a desired location via a pressure valve 8, an air pipe 11, an air cooler 10 and a service pipe 12. The pressure valve 8 being operated by a pressure switch 17 opens when the pressure in the accumulator 5 is beyond a preset value.
The oil 6a which is exhausted from the accumulator 5 through a first oil transmission pipe 23 is selectively supplied by a temperature regulator 15 to the first oil supply pipe 21 and a second oil transmission pipe 24. That is, during the initial operation of the compressor, when the temperature of the oil 6a is relatively low, the oil is transferred through the first oil supply pipe 21 and supplied to the rotor 3a. When the temperature of the oil 6a is relatively high, the oil is supplied to the oil cooler 20 through the second oil transmission pipe 24. The oil supplied to the oil cooler 20 is cooled and then supplied to the temperature regulator 15 through a second oil supply pipe 22. The oil passes through an oil filter 16 and flows into the first oil supply pipe 21 by the operation of the temperature regulator 15.
The above conventional compressor system has the following problems.
First, since the compressor main unit 3, the temperature regulator 15 and the oil filter 16 are connected to the accumulator 5 by the exhaust pipe 3b and the first oil transmission pipe 23, the compressor system is complicated and the size is large. Thus, loss of pressure in the pipes increases, the system becomes susceptible to vibrations, and a great amount of oil is required.
Second, since the accumulator 5 is usually fabricated by molding or welding several metal plates, the production thereof is slow.
Third, since the output of the exhaust pipe 3b is installed at a place adjacent to the inlet of the oil separator 7, most of the oil included in the compressed air splashed to the accumulator 5 does not precipitate but passes through the oil separator together with the compressed air. Thus, the efficiency of oil separation is lowered and also the life span thereof is shortened.